Lock nut



June 16, 1936. D. J? COLLINS Patented June 16.1936

PATENT OFFICE Application February 13, .1935, serial No. 6,358

In Australia July 31, 1934 v 2 cl ims. (01. 151-12) The object of this invention 'is to provide anut ward influences, and yet is capable of being unscrewed and removed as occasion may require.

With the above-stated object the invention consists in a nut for use on a threaded element formed with one or more longitudinal grooves or notches on its threaded surfaceysaid nut being formed with a slot parallel with the bottom face of the nut and meeting the bore, and including a ratchet-pawl pivoted in said recess and at one end formed as a tooth to engage any one of said grooves or notches on the threaded element, a spring urging the pawl into such engagement to prevent the nut from slacking back, and means incorporated in and constituting part of the nut for moving the pawl to and retaining it in disengaging position to permit the nut to be unscrewed. The tooth of the pawl is preferably shaped to constitute threads adapted to register with those on the bolt, so that the tips of the later will not be injured as the nut is screwed up, nor the ends of the threads burred.

The invention may be embodied in different forms, and for the purpose of more fully explaining it, reference is made to the accompanying drawing which depicts two practical embodiments each a modification of the other.

In the drawing, 7

Figure 1 is a perspective view showing a bolt and nut embodying the invention in one form;

Figure 2 is a sectional plan on plane 2, 2 of Figure'l;

Figure 3 is a sectional elevation,

Figure 4 is a sectional elevation on line 4, 4 of Figure 2, and V Figure 5 is a perspective view of the pawl and spring,

Figure 6 is a perspective View showing a modified construction'of nut on a bolt, 7

Figure 7 a sectional plan on plane I, I of Figure 6, and V Figure 8 a part sectional elevation on line 8, 8

of Figure 7.

The nut I2 is of conventional shape and is adapted to screw on to a bolt 13 which has a plurality of longitudinal grooves or notches l4, I4 on its threaded portion. In the nut is cut a slot iii of sufiicient depth to meet the bore of the nut and in the recess is a ratchet-pawl l6 pivotally mounted on a pin I! fitted in a hole bored perpendicularly from the top or bottom face of the nut. The

. formed and arranged that when the nut is screwed pawl is formed with a tooth l 8 which, asclearly wn i ie efi s er e r readsdlw re ister with the threadsonthe bolt,thi;s iormati qn rendering it necessary that the notches I4 on the bolt are deeper than the threads thereon, in order to provide an abutment surface below the roots of the threads. 1 The tooth of the pawl is urged towards the bolt by a bow-spring l9 anchored at one end in a kerf 2D in the pawl, and bearing at its other end 10 against an abutment.

In the construction shown in Figures 1 to 4 inclusive, the spring abuts against a cover plate 2| rotatable on a pivot screw 22 and formed with a slot 23 normally in register with the slot in the nut, said plate being rounded off at the lower right-hand corner as at 24 to permit it to be swung clockwise on its pivot when the base of the nut is hearing against a surface. The pawl is so on a bolt and the operative end of the pawl en- 20 gages one of the notches of the bolt, the tail of the pawl projects into the slot 23 of the plate when the latter is in normal position as shown in Figure 1; but when the plate is rotated in clock- 25 wise direction the end of slot 23 acts as a cam to inwardly move the tail end of pawl l6 and withdraw the tooth IB from engagement with the notch I4 of the bolt I3 so that the nut l2 may be slacked back. The arrangement of the plate 2| in relation to the nut is such that the outer surface of the plate constitutes one of the flats of the nut.

In the modification shown in Figures 6, 'l-and 8, the cover plate 2 l is slidably mounted in bevelled guides 25, 25 cut in that side of the nut in which the slot or kerf is cut, and is movable vertically. When the plate 21 is in the position shown in Figure 8 its slot 23 is in register with the tail of the pawl l1 and the tooth l8 of the 0 latter is in engagement with the bolt under the influence of spring l9. To release the nut the plate 21 is raised and the bevelled edge 26 (Fig- 'ure 8) of its slot 23 acts as a cam to push in- V wardly the tail of the pawl and retract the tooth. 45

slot extending from its periphery to its bore, a ratchet-pawl pivotally mounted in said slot and wholly located at all times within the confines of the nut, a spring urging the operative end of said pawl into the bore of the nut to engage one of the said grooves in the bolt, 2. plate carried by the nut, the outer faces of the plate constituting parts of the regular peripheral contour of the nut, means to mount the plate within the compass of the nut for movement in its own plane over said radial slot, said plate having a slotted portion with a cam part registering with said slot in the nut into which the tail end of said pawl projects, said plate when moved in its plane from its normal or inoperative position serving to retract the operative end of said pawl and close the end of said slot in the nut in which the pawl is located thereby holding the pawl inoperative by contact of the pawl with the inner face of said plate.

2. A look nut for use on a bolt or the like having longitudinal ratchet grooves or notches on its threaded surface; said nut being in the form of a regular polygon in plan view and having a radial slot extending from its periphery to its bore, a ratchet-pawl pivotally mounted in said slot and wholly located at all times within the confines of the nut, a spring urging the operative end of said pawl into the bore of the nut to engage one of the said grooves in the bolt, a plate carried by the nut, the outer faces of the plate constituting parts of the regular peripheral contour of the nut, means to mount the plate within the compass of the nut for movement in its own plane over said radial slot, said plate having a slotted portion with a cam part registering with said slot in the nut into which the tail end of said pawl projects, said plate when moved in its plane from its normal or inoperative position serving to retract the operative end of said pawl and close the end of said slot in the nut in which the pawl is located thereby holding the pawl inoperative by contact of the pawl with the inner face of said plate, said spring being carried by said pawl and continuously engaging said slidable plate to maintain the spring tension.

DAVID JOHN COLLINS. 

